text: """Minimal script to reproduce our nasty reference counting bug.
  
  The problem is related to https://bugs.launchpad.net/ipython/+bug/269966
  
  The original fix for that appeared to work, but John D. Hunter found a
  matplotlib example which, when run twice in a row, would break.  The problem
  were references held by open figures to internals of Tkinter.
  
  This code reproduces the problem that John saw, without matplotlib.
  
  This script is meant to be called by other parts of the test suite that call it
  via %run as if it were executed interactively by the user.  As of 2009-04-13,
  test_magic.py calls it.
  """
  
  #-----------------------------------------------------------------------------
  # Module imports
  #-----------------------------------------------------------------------------
  import sys
  
  from IPython import ipapi
  
  #-----------------------------------------------------------------------------
  # Globals
  #-----------------------------------------------------------------------------
  ip = ipapi.get()
  
  if not '_refbug_cache' in ip.user_ns:
      ip.user_ns['_refbug_cache'] = []
  
  
  aglobal = 'Hello'
  def f():
      return aglobal
  
  cache = ip.user_ns['_refbug_cache']
  cache.append(f)
  
  def call_f():
      for func in cache:
          print 'lowercased:',func().lower()
  